Efforts to repeal the 1996 Defense of Marriage Act are in full swing, as a major lawsuit advances, another lawsuit is filed, and a Senate panel meets soon to consider legislation to overturn the law.

“We are working hard to strike the blow that will end DOMA,” said Mary Bonuato, civil rights project director at Gay & Lesbian Advocates & Defenders (GLAD) and lead attorney in Gill v. Office of Personnel Management.

Gill is one of several lawsuits filed by gay spouses who say their lives have been injured by DOMA, which defines marriage, for federal purposes, as the union of a man and a woman. DOMA also tells states they do not have to recognize out-of-state gay unions.

GLAD attorneys are asking the 1st U.S. Circuit Court of Appeals to uphold the July 2010 ruling of U.S. District Court Judge Joseph L. Tauro that said DOMA is unconstitutional. The GLAD brief, filed Oct. 27, maintains that the only purpose of DOMA is “impermissible animus” against gays, and that there are no rational justifications for keeping the law on the books.

Only states can decide marriage laws, not Congress, GLAD attorneys said in their brief. Moreover, Congress’ arguments that it should favor heterosexual marriage and procreation do not hold up, especially in light of the real discrimination afforded to same-sex couples, the lawyers said.

Instead, the one thing DOMA does is reflect “moral disapproval of homosexuality” - that is “the only explanation for DOMA that makes any sense,” they said, citing the now-deceased Sen. Jesse Helms, North Carolina Republican, who said in 1996 that DOMA should be enacted because “the moral and spiritual survival of this nation” was at stake.

A response is due by Dec. 1 from the House of Representatives’ Bipartisan Legal Advisory Group, represented by Paul D. Clement and others at Bancroft PLLC.

Separately, also on Oct. 27, several members of the armed services filed a lawsuit against DOMA in U.S. District Court in Massachusetts.

It’s “a threat to national security” when the military is unable to promise legally married same-sex service members that their families will be provided for in their absence, Army Maj. Shannon McLaughlin and 15 other plaintiffs argued in their complaint. They are represented by lawyers with the Servicemembers Legal Defense Network and Chadbourne & Parke LLP in New York City.

The service members want to be counted as married for such military purposes as medical and dental coverage, housing allowances, travel and transportation allowances, visitation rights in military hospitals, survivor benefits and the right to be buried together in military cemeteries.

Eileen Lainez, spokeswoman for the Defense Department, said, “We will carefully evaluate the complaint, and we will consult [the Department of Justice]. In the meantime, we will continue to follow the law.”

“Service members continue to have some benefits for which they may designate beneficiaries, regardless of sexual orientation,” she added. Also, in connection with the repeal of “Don’t Ask, Don’t Tell,” the department is “engaged in a careful and deliberate review of the possibility of extending eligibility for benefits, if legally permitted, to other individuals, including same-sex partners.”

Later this week, a Senate committee will take up a bill that would repeal DOMA.

The Senate Judiciary Committee will meet Nov. 3 to mark up the Respect for Marriage Act, said Sen. Patrick J. Leahy, Vermont Democrat and committee chairman.

The Senate bill, introduced in March by Sen. Dianne Feinstein, California Democrat, has 30 co-sponsors. A House version of the Respect for Marriage Act, introduced by Rep. Jerrold Nadler, New York Democrat, has 128 co-sponsors.